CONSIDERATIONS IN DEVELOPING A NEW FISSILE TRANSPORT PACKAGE

This paper identifies and illustrates the typical activities and skills involved in the design and development of a new package. The activities described are modelled on those undertaken by Rolls-Royce Power Engineering in designing, developing and licensing the NMTSP package for carrying fresh fuel. It illustrates the wide range of skills required and the need for a flexible approach in deriving the final design. Topics considered are: • Details of the payload to be carried, which includes assessments of containment boundary, fragility, thermal durability and means of criticality suppression; • Space and weight constraints for the final package design; • User requirements, eg stacking, ease of use, maintainability; • Lifetime and whether used for transport only, or storage and transport; • Permeation and humidity control; • Material choices, future-proofing, and the trade off between initial and through-life costs; • Transport modes and the effects on design; • Design ambient temperature range; • Pressurisation; • Testing for material characterisation; • Structural testing on design features; • Thermal testing of barrier materials and sections; • Scoping calculations for impact; • Lifting and tie-down features; • Lid joint development, including bolting sizing; • Lid bolt testing; • Adverse material property combinations; • Detailed impact analysis and predictions for drop testing; • Criticality modelling and confinement boundary for normal and accident conditions; • Modifications through manufacture; • Test programme, including cumulative damage for normal and accident conditions; • Development of drop target; • Drop and stacking test results; • Correlation and validation between test and impact analyses; Ancillary equipment, eg lifting and transport; • Licensing. This list is not exhaustive, and not every step will be required for all package designs, but the intent is to illustrate a typical process.